1. Field
The present general inventive concept generally relates to providing a pressure switch for a dust sensor applied to a vacuum cleaner, and more particularly, to providing a pressure switch for turning on and/or off a dust sensor that is installed on a suction path to sense dust flowing into a vacuum cleaner.
2. Description of the Related Art
In general, a pressure switch for a dust sensor applied to a vacuum cleaner senses a pressure change in one place of an extension tube to turn on and/or off the dust sensor according to the pressure change.
A pressure switch as described above includes a body part and a rubber cap that is combined with an upper part of the body part. In this case, a preset space part or space is formed inside the rubber cap. The preset space is connected to the extension tube and thus shrinks due to a negative pressure formed when a suction pressure acts in the extension tube.
A coil spring is disposed in the preset space part, and a copper plate is disposed on an internal surface of the rubber cap so as to enable an upper end of the coil spring to be electrically connected to the copper plate. In this case, a lower end of the coil spring is electrically connected to a first terminal of the dust sensor. Also, a second terminal is combined with the body part to be disposed in the preset space part and is electrically connected to the dust sensor.
Since the coil spring simultaneously elastically supports an upper surface of the body part and the internal surface of the rubber cap, the copper plate disposed inside the rubber cap and the second terminal are separated from each other. If the negative pressure is formed in the preset space part in this state, the rubber cap shrinks so as to connect the copper plate to the second terminal and to activate the dust sensor. On the contrary, if the negative pressure is released from the preset space part, the rubber cap returns to an original shape thereof due to an elastic force of the coil spring. Therefore, the copper plate is disconnected from the second terminal, and thus deactivating or turning off the dust sensor.
In the pressure switch, the first terminal, the coil spring, the copper plate, and the second terminal may be sequentially powered or electrified to activate the dust sensor. However, the pressure switch has various failure factors at connection points between the first terminal and the coil spring, between the coil spring and the copper plate, and between the copper plate and the second terminal. For example, errors may occur in connection and disconnection operations between the first and second terminals due to various failure factors such as a connection failure or a removal of the coil spring caused by corrosion, a non-return to an original shape of the coil spring caused by twisting of the coil spring occurring when the coil spring is compressed and then expanded to an original shape thereof, a decrease in the elastic force of the coil spring caused by a long period usage, or the like.
Also, the pressure switch for the dust sensor needs an additional cable and an additional connector because of a complicated terminal structure as described above. Therefore, unit prices of products increase, and an assembling property is poor.